Broker-dealer systems for automated trading of securities need to be fast. Broker-dealer systems receive orders from customers, send the orders to markets, receive responses from markets, and communicate order status to customers. Orders are sent to markets through data communications ports. Responses are received from markets through data communications ports. Ports are dedicated to particular markets. Data communications ports have limitations upon the number of orders that can be sent through them in a particular period of time or the number of orders without acknowledgments that can be sent through them. If more orders arrive than can be sent through a port in a particular period of time, the broker-dealer system is slowed. If a port partially fails or is slowed for mechanical or electrical reasons, the broker-dealer system is slowed. If a port fails completely, the broker-dealer system is disabled with regard to the market served by that port.
Broker-dealers often add additional ports to their systems, so that more than one port is dedicated to a particular market. Adding ports improves overall throughput of orders to markets and reduces the risk of being completely disabled with respect to a market if a port fails. System performance can still vary widely, however, from the point of view of a customer whose order is sent through a port that is slowed or stopped by overload or mechanical failure. Such a customer experiences the harmful effect of a lack of balance in the communications load among the ports for the market to which the customer's order was intended. Methods and systems are needed for balancing the communications loads among ports for markets in support of the overall quality of data communications in broker-dealer systems.